"It is comfortable to see the standard of reason at length erected, after so many ages, during which the human mind has been held in vassalage by kings, priests, and nobles; and it is honorable for us to have produced the first legislature who had the courage to declare that the reason of man may be trusted with the formation of his own opinions." --Thomas Jefferson to James Madison, 1786.
"I am... against all violations of the Constitution to silence by force and not by reason the complaints or criticisms, just or unjust, of our citizens against the conduct of their agents." --Thomas Jefferson to Elbridge Gerry, 1799.
"Ignorance and bigotry, like other insanities, are incapable of self-government." --Thomas Jefferson to Lafayette, 1817.
"What an effort... of bigotry in politics and religion have we gone through! The barbarians really flattered themselves they should be able to bring back the times of Vandalism, when ignorance put everything into the hands of power and priestcraft. All advances in science were proscribed as innovations. They pretended to praise and encourage education, but it was to be the education of our ancestors. We were to look backwards, not forwards, for improvement." --Thomas Jefferson to Joseph Priestley, 1801.
"I am not myself apt to be alarmed at innovations recommended by reason. That dread belongs to those whose interests or prejudices shrink from the advance of truth and science." --Thomas Jefferson to John Manners, 1814. ME 14:103
"I am for encouraging the progress of science in all its branches, and not for raising a hue and cry against the sacred name of philosophy; for awing the human mind by stories of raw-head and bloody bones to a distrust of its own vision, and to repose implicitly on that of others; to go backwards instead of forwards to look for improvement; to believe that government, religion, morality and every other science were in the highest perfection in the ages of the darkest ignorance, and that nothing can ever be decided more perfect than what was established by our forefathers." --Thomas Jefferson to Elbridge Gerry, 1799.
"One of the questions... on which our parties took different sides was on the improvability of the human mind in science, in ethics, in government, etc. Those who advocated reformation of institutions pari passu with the progress of science maintained that no definite limits could be assigned to that progress. The enemies of reform, on the other hand, denied improvement and advocated steady adherence to the principles, practices and institutions of our fathers, which they represented as the consummation of wisdom and acme of excellence, beyond which the human mind could never advance... [They predicted that] freedom of inquiry... will produce nothing more worthy of transmission to posterity than the principles, institutions and systems of education received from their ancestors... [But we] possess... too much science not to see how much is still ahead of [us], unexplained and unexplored. [Our] own consciousness must place [us] as far before our ancestors as in the rear of our posterity." --Thomas Jefferson to John Adams, 1813.
"I join [with others] in branding as cowardly the idea that the human mind is incapable of further advance. This is precisely the doctrine which the present despots of the earth are inculcating and their friends here re-echoing and applying especially to religion and politics: 'that it is not probable that anything better will be discovered than what was known to our fathers.' We are to look backwards, then, and not forwards for the improvement of science and to find it amidst feudal barbarisms and the fires of Spital-fields. But thank heaven the American mind is already too much opened to listen to these impostures; and while the art of printing is left to us, science can never be retrograde. What is once acquired of real knowledge can never be lost." --Thomas Jefferson to William Green Munford, 1799.
"It is error alone which needs the support of government. Truth can stand by itself." --Thomas Jefferson: Notes on Virginia Q.XVII, 1782.
"Every man's reason [is] his own rightful umpire. This principle, with that of acquiescence in the will of the majority, will preserve us free and prosperous as long as they are sacredly observed." --Thomas Jefferson to John F. Watson, 1814.
"I hold it... certain, that to open the doors of truth and to fortify the habit of testing everything by reason are the most effectual manacles we can rivet on the hands of our successors to prevent their manacling the people with their own consent." --Thomas Jefferson to John Tyler, 1804.
"Shake off all the fears and servile prejudices under which weak minds are servilely crouched. Fix reason firmly in her seat, and call to her tribunal every fact, every opinion. Question with boldness even the existence of a God; because, if there be one, he must more approve of the homage of reason, than that of blindfolded fear." --Thomas Jefferson to Peter Carr, 1787.
"There is not a truth existing which I fear or would wish unknown to the whole world." --Thomas Jefferson to Henry Lee, 1826.
"There is not a truth on earth which I fear or would disguise. But secret slanders cannot be disarmed, because they are secret." --Thomas Jefferson to William Duane, 1806.
"The Gothic idea that we were to look backwards instead of forwards for the improvement of the human mind, and to recur to the annals of our ancestors for what is most perfect in government, in religion and in learning, is worthy of those bigots in religion and government by whom it has been recommended, and whose purposes it would answer. But it is not an idea which this country will endure." --Thomas Jefferson to Joseph Priestley, 1800.
"We believed that men, enjoying in ease and security the full fruits of their own industry, enlisted by all their interests on the side of law and order, habituated to think for themselves and to follow their reason as their guide, would be more easily and safely governed than with minds nourished in error and vitiated and debased... by ignorance, indigence and oppression." --Thomas Jefferson to William Johnson, 1823.
